检索结果-南通市图书馆

Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

Research in Astronomy and Astrophysics 2016年第4期16卷 7-14页

作者： Debbijoy Bhattacharya Parameswaran Sreekumar Banibrata Mukhopadhyay ishan.Tomar Manipal Centre for Natural Sciences Manipal UniversityManipal 576104India Indian Institute of Astrophysics Bangalore 560034India Astronomy and Astrophysics Programme Department of PhysicsIndian Institute of ScienceBangalore 560012India Space Astronomy Group ISRO Satellite CentreKarthik NagarBangalore 560037India

Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes： fiat spectrum radio quasars （FSRQs） and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in ＂7-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in 7-ray luminosity between the two classes is significantly reduced. In order to ex- plain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.

关键词： BL Lacertae objects: general -- quasars: general -- galaxies: jets -- black hole physics --relativistic processes -- gravitation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The divergence of nearby trajectories in soft-sphere DEM

引用

Particuology 2022年第4期20卷 1-8页

作者： William D.Fullmer Roberto Porcu Jordan Musser Ann S.Almgren ishan.Srivastava National Energy Technology Laboratory MorgantownWV 26507USA NETL Support Contractor MorgantownWV 26507USA Center for Computational Sciences and Engineering.Lawrence Berkeley National Laboratory BerkeleyCA 94720USA

The n-body instability is investigated with the soft-sphere discrete element *** divergence of nearby trajectories is quantifed by the dynamical memory *** the inverse proportionality between the dynamical memory time and the largest Lyapunov exponent,the soft-sphere discrete ele-ment method results are compared to previous hard-sphere molecular dynamics data for the first *** agreement is observed at low concentrations and the degree of instability is shown to increase asymptotically with increasing spring *** particle concentrations above 30%,the soft-sphere Lya-punov exponents increase faster than the corresponding hard-sphere *** paper concludes with a demonstration of how this case study may be used in conjunction with regression testing and code verification activities.

关键词： Soft-sphere DEM Chaos Lyapunov exponent

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Proposed numerical and machine learning models for fiber-reinforced polymer concrete-steel hollow and solid elliptical columns

引用

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1169-1194页

作者： Tang QIONG ishan.JHA Alireza BAHRAMI Haytham F.ISLEEM Rakesh KUMAR Pijush SAMUI School of Applied Technologies Qujing Normal UniversityQujing 655011China Department of Civil Engineering Indian Institute of Technology-BHUVaranasi 221005India Department of Building Engineering Energy Systems and Sustainability ScienceFaculty of Engineering and Sustainable DevelopmentUniversity of GävleGävle 80176Sweden Department of Civil Engineering National Institute of Technology-PatnaPatna 800005India

This study employs a hybrid approach,integrating finite element method(FEM)simulations with machine learning(ML)techniques to investigate the structural performance of double-skin tubular columns(DSTCs)reinforced with glass fiber-reinforced polymer(GFRP).The investigation involves a comprehensive examination of critical parameters,including aspect ratio,concrete strength,number of GFRP confinement layers,and dimensions of steel tubes used in DSTCs,through comparative analyses and parametric *** ensure the credibility of the findings,the results are rigorously validated against experimental data,establishing the precision and trustworthiness of the *** present research work examines the use of the columns with elliptical cross-sections and contributes valuable insights into the application of FEM and ML in the design and evaluation of structural systems within the field of structural engineering.

关键词： elliptical column fiber-reinforced polymer machine learning finite element method ABAQUS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frequency Domain Convolution of Rational Transfer Functions

引用

Journal of Applied Mathematics and Physics 2022年第6期10卷 2117-2129页

作者： ishan.Kar Prospect High School Saratoga USA

The convolution of two rational transfer functions is also rational, but a formula for the convolution has never been derived. This paper introduces a formula for the convolution of two rational functions in the frequency domain by two new methods. The first method involves a partial fraction expansion of the rational transfer functions where the problem gets reduced to the sum of the convolution of the partial fractions of the two functions, each of which can be solved by a new formula. Since the calculation of the roots of a high-order polynomial can be very time-consuming, we also demonstrate new methods for performing the convolution without calculating these roots or undergoing partial fraction expansion. The convolution of two rational Laplace transform denominators can be calculated using their resultant, while that of the two rational Z-transform transfer functions can be found using Newton’s identities. The numerator can be easily found by multiplying the numerator with the initial values of the power series of the result.

关键词： Z-Transform Laplace Transform Frequency Domain Convolution

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Incidence and Survivability of Acute Lymphocytic Leukemia Patients in the United States: Analysis of SEER Data Set from 2000-2019

引用

Journal of Cancer Therapy 2024年第4期15卷 141-163页

作者： ishan.Ghosh Sudipto Mukherjee Department of Biology Rockhurst University Kansas City Missouri USA Hematology and Medical Oncology Cleveland Clinic Cleveland Ohio USA

The main goal of this research is to assess the impact of race, age at diagnosis, sex, and phenotype on the incidence and survivability of acute lymphocytic leukemia (ALL) among patients in the United States. By taking these factors into account, the study aims to explore how existing cancer registry data can aid in the early detection and effective treatment of ALL in patients. Our hypothesis was that statistically significant correlations exist between race, age at which patients were diagnosed, sex, and phenotype of the ALL patients, and their rate of incidence and survivability data were evaluated using SEER*Stat statistical software from National Cancer Institute. Analysis of the incidence data revealed that a higher prevalence of ALL was among the Caucasian population. The majority of ALL cases (59%) occurred in patients aged between 0 to 19 years at the time of diagnosis, and 56% of the affected individuals were male. The B-cell phenotype was predominantly associated with ALL cases (73%). When analyzing survivability data, it was observed that the 5-year survival rates slightly exceeded the 10-year survival rates for the respective demographics. Survivability rates of African Americans patients were the lowest compared to Caucasian, Asian, Pacific Islanders, Alaskan Native, Native Americans and others. Survivability rates progressively decreased for older patients. Moreover, this study investigated the typical treatment methods applied to ALL patients, mainly comprising chemotherapy, with occasional supplementation of radiation therapy as required. The study demonstrated the considerable efficacy of chemotherapy in enhancing patients’ chances of survival, while those who remained untreated faced a less favorable prognosis from the disease. Although a significant amount of data and information exists, this study can help doctors in the future by diagnosing patients with certain characteristics. It will further assist the health care professionals in screening

关键词： Acute Lymphocytic Leukemia Survivability Incidence Demography SEER Data Set

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy <i>β</i>-Conformal Change and Special Finsler Spaces

引用

Journal of Modern Physics 2013年第7期4卷 983-990页

作者： Amr Soleiman Amira A. ishan Department of Mathematics Faculty of Science Benha University Benha Egypt Department of Mathematics Taif University Makkah KSA

The main aim of the present paper is to establish an intrinsic investigation of the energy β-conformal change of the most important special Finsler spaces, namely, Ch-recurrent, Cv-recurrent, C0-recurrent, Sv-recurrent, quasi-C-reducible, semi-C-reducible, C-reducible, P-reducible, C2-like, S3-like, P2-like and h-isotropic, ···, etc. Necessary and sufficient conditions for such special Finsler manifolds to be invariant under an energy β-conformal change are obtained. It should be pointed out that the present work is formulated in a prospective modern coordinate-free form.

关键词： Energy β-Conformal Change Ch-Recurrent Cv-Recurrent C0-Recurrent C2-Like Quasi-C-Reducible C-Reducible Berwald Space Sv-Recurrent S3-Like P2-Like h-Isotropic

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Emerging Frontiers in Vaccine Development: A Review of Changing Paradigm

引用

Journal of Biosciences and Medicines 2022年第7期10卷 123-145页

作者： ishan.Ghosh Mohit D. Gandhi Huntington Beach High School Huntington Beach USA Quantitative Pharmacology and Pharmacometrics ICON Early Clinical Development Lenexa USA

The technology behind vaccine development varies significantly from one vaccine to another depending on the time when the vaccine was first developed. Over the years, the vaccine innovation time has significantly shortened with the advancement of knowledge in the fields of molecular and cell biology, and discoveries in the field of biotechnology. The first vaccines created were tested in a kind of trial-and-error approach which sometimes had deadly side effects. These vaccines used either living, weakened, or completely dead pathogens. The use of whole pathogen vaccines was seen to be time consuming and unpredictable because even though it would cause an immune response, it could vary from person to person, and always had the risk of pathogens returning to virulence causing sometimes fatal outcomes. The next major technology used to create vaccines was subunit vaccines which utilize purified antigens inactivated through various methods. This technology is quite prevalent among the vaccines that are currently in circulation, making them quite effective, and free from fatal side effects. The viral vector vaccine technology has been around for a few decades and utilizes knowledge of molecular genetics to the greatest extent. It uses intermediate vectors to deliver genetic instructions to trigger an immune response within the subject body. The introduction of nucleic acid vaccines is the newest technology and has come to a great deal of attention during the SARS-CoV-2 immunization efforts. The technology primarily utilizes the delivery of genetic information using messenger ribonucleic acid (mRNA) to create characteristic pathogen-specific proteins that in turn generate an immune response in the recipients.

关键词： Vaccine Technology DNA Vaccine mRNA Vaccine COVID-19 Vaccine Vaccine Development

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A rare case of Staphylococcus lugdunensis septicemia associated with myocarditis and atrioventricular block

引用

Journal of Geriatric Cardiology 2019年第1期16卷 63-66页

作者： Alex Tsz Lai Nganh Sharen Lee Tong LIU Mark Tam Ka Hou Christien Li Michelle Vangi Wong Michael Huen Sum Lam Gary Tse ishan.Lakhani Department of Medicine and Therapeutics Faculty of MedicineChinese University of Hong KongHong KongChina Li Ka Shing Institute of Health Sciences Faculty of MedicineChinese University of Hong KongHong KongChina Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of CardiologyTianjin Institute oj CardiologySecond Hospital of Tianjin Medical UniversityTianjinChina Faculty of Medicine Newcastle University.United Kingdom Faculty of Health and Wellbeing Sheffield Hallam UniversityUnited Kingdom

Myocarditis is a relatively rare,possibly life-threatening disease characterized by the inflammation of the myocardium.111 The disease pathogenesis is primarily initiated by acute injury and necrosis of cardiomyocytes,leading to an inflammatory response mediated by the immune system that can potentially cause further aggravation of myocardial damage and organ *** in patients with myocarditis depends on the clinical presentation,which ranges from an asymptomatic disease course to the concomitant development of cardiac arrhythmias,heart failure,cardiogenic shock and even the occurrence of death in extreme cases[1].

关键词： Atrioventricular block Conduction Inflammation Myocarditis Staphylococcus lugdunensis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Atypical Presentations of COVID-19

引用

Advances in Infectious Diseases 2020年第3期10卷 136-142页

作者： Deepthi Jayasekara Suranjith L. Seneviratne Arindra Jayasekara ishan.De Zoysa Department of Infectious Diseases Western University Pomona USA Emanate Health West Covina USA Department of Surgery University of Colombo Colombo Sri Lanka Department of Clinical Immunology Royal Free Hospital London UK Tulane University New Orleans USA

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, emerged in Wuhan, China in December 2019. It has now spread to all parts of the world and as of 26th July 2020, more than 16 million cases and over 600,000 deaths have been reported. The commonest presentation is respiratory in nature with non-productive cough, fever and shortness of breath. Some COVID-19 patients have had atypical or unusual presentations involving the neurological, metabolic, gastrointestinal, renal, haematological, cutaneous and cardiovascular systems. In this mini-review, we have outlined the main atypical or unusual clinical presentations of COVID-19.

关键词： COVID-19 SARS-CoV-2 Atypical Presentation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CT of hepatocellular carcinoma in non-alcoholic fatty liver disease: imaging characteristics and inter-rater agreement

引用

Hepatoma Research 2019年第10期5卷 42-52页

作者： ishan.Garg Scott M.Thompson Shannon P.Sheedy Taofic Mounajjed Ashish Khandelwal Eric C.Ehman Candice A.Bookwalter Sudhakar K.Venkatesh Department of Radiology Mayo Clinic College of MedicineRochesterMN 55905USA Department of Laboratory Medicine and Pathology Mayo Clinic College of MedicineRochesterMN 55905USA

Aim:To determine the computed tomography(CT)features of non-alcoholic fatty liver disease(NAFLD)associated hepatocellular carcinoma(HCC).Methods:In this institutional review board approved study,we reviewed 38 patients with NAFLD(68.4%male;mean age 63 years)with histology confirmed HCC and triphasic liver *** images were independently reviewed by four readers blinded to clinical and pathology *** reviewers assessed HCC for arterial phase hyper enhancement(APHE),portal venous phase washout(PVWO),delayed phase washout(DPWO),and enhancing *** of cirrhotic morphology and portal hypertension(PH)were also *** final CT features were determined by majority and a fifth reader reviewed cases lacking ***-rater agreement was determined by prevalence-adjusted ***:Mean HCC size was 3.6±2.8 cm(range,1.1-16.0 cm).The HCCs showed APHE in 92.1%,PVWO in 55.3%,DPWO in 81.6%,and enhancing capsule in 44.7%.Cirrhotic morphology was present in 65.8%and PH in 63.2%.Inter-rater agreement was moderate to almost perfect for APHE(0.74-1.0),cirrhosis(0.79-0.89),and PH(0.79-0.95),weak to perfect for DPWO(0.47-0.95)and poor for PVWO(0-0.42). ;Conclusion:NAFLD associated HCC demonstrate less frequent portal venous washout on CT which may affect their imaging diagnosis.

关键词： Hepatocellular carcinoma computed tomography fatty liver inter-rater agreement non-alcoholic fatty liver disease

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：